RESUMEN

BACKGROUND: Patients' increasing interest in achieving optimal cosmetic outcomes and the widespread use of ultrathin ceramic veneers offer advantages such as high esthetic results and long-term durability. Several issues related to tooth preparation have been raised, including dental sensitivity, periodontal diseases, and increased treatment phases, in addition to complications associated with previous procedures, the treatment of which remains controversial to date. With the advancement of dental ceramic and its manufacturing techniques, it was widely used to manufacture ultrathin ceramic veneers with minimal preparation. Issues such as fracture and abfraction are the most common in ceramic veneers made of feldspathic ceramic due to their weak mechanical properties against various forces, which led to the emergence of lithium disilicate glass-ceramic manufactured using the heat-press technique. This has resulted in ultrathin ceramic veneers with a thickness of up to 0.1-0.2 mm easily bonded and finished as they have high mechanical properties and esthetic qualities that mimic natural tooth color and shape. The current cohort study aimed to evaluate the success rates of this kind of treatment for patients treated at our department. MATERIALS AND METHODS: This observational cohort study's sample comprised 60 ultrathin ceramic veneers manufactured from lithium disilicate glass-ceramic bonded to nonprepared upper teeth. The clinical performance of the studied sample was evaluated and monitored at monthly intervals (one month, three months, six months, and one year) using the clinical success evaluation based on Walton's principles adopted for evaluating the success and failure of fixed restorations. RESULTS: Ultrathin ceramic veneers made from lithium disilicate glass-ceramic, bonded to nonprepared teeth, proved to be a successful clinical and esthetic treatment option, with a clinical success rate of 100% during the entire follow-up period. CONCLUSIONS: This study's findings indicate that ultrathin ceramic veneers made from lithium disilicate glass-ceramic, bonded to nonprepared teeth, are a successful clinical and esthetic treatment option, with a clinical success rate of 100% during the entire follow-up period.

RESUMEN

Sonopiezocatalytic therapy is an emerging therapeutic strategy that utilizes ultrasound irradiation to activate piezoelectric materials, inducing polarization and energy band bending to facilitate the generation of reactive oxygen species (ROS). However, the efficient generation of ROS is hindered by the long distance of charge migration from the bulk to the material surface. Herein, atomically thin Bi2O2(OH)(NO3) (AT-BON) nanosheets are rationally engineered through disrupting the weaker hydrogen bonds within the [OH] and [NO3] layer in the bulk material. The ultrathin structure of AT-BON piezocatalytic nanosheets shortens the migration distance of carriers, expands the specific surface area, and accelerates the charge transfer efficiency, showcasing a natural advantage in ROS generation. Importantly, the non-centrosymmetric polar crystal structure grants the nanosheets the ability to separate electron-hole pairs. Under ultrasonic mechanical stress, Bi2O2(OH)(NO3) nanosheets with the remarkable piezoelectric feature exhibit the desirable in vivo antineoplastic outcomes in both breast cancer model and liver cancer model. Especially, the AT-BON-induced ROS bursts lead to the activation of the Caspase-1-driven pyroptosis pathway. This study highlights the beneficial impact of bulk material thinning on enhancing ROS generation efficiency and anti-cancer effects.

RESUMEN

Lithium-sulfur (Li-S) batteries are considered as promising energy storage systems due to the high energy density of 2600 W h kg-1. However, the practical application of Li-S batteries is hindered by the inadequate conductivity of sulfur and Li2S, as well as the shuttle effect caused by polysulfides during the charge-discharge process. Introducing a conductive interlayer between the cathode and the separator to physically resist polysulfides represents an effective and straightforward approach to mitigate the shuttle effect in Li-S batteries. In this paper, an ultrathin (<1 µm) 2D-2D MXene-LDH interlayer with high polysulfide adsorption ability was introduced to Li-S batteries. The synergistic effect between MXene and layered double hydroxide greatly improved the adsorption effect of the interlayers: the conductive Ti3C2Tx MXene chemically adsorbs polysulfides and promotes their fast transfer, and the NiCo-LDH alleviates the restack of MXene and facilitates Li+ diffusion. After inserting the MXene-LDH interlayer, the Li-S batteries exhibit an enhanced specific capacity of 1137.6 mA h g-1 at 0.1 C and retain 622.6 mA h g-1 after 100 cycles. The ultrathin 2D-2D interlayer offers a feasible way for the development of highly efficient and lightweight interlayers in Li-S batteries.

RESUMEN

Direct methanol fuel cells rely on the efficiency of their anode/cathode electrocatalysts to facilitate the methanol oxidation reaction and oxygen reduction reaction, respectively. Platinum-based nanocatalysts are at the forefront due to their superior catalytic properties. However, the high-cost, scarcity, and low CO tolerance of platinum pose challenges for the scalable application of DMFCs. Herein, we report novel ultrathin ternary PtNiRu alloy nanowires to improve Pt utilization and CO tolerance. These novel electrocatalysts incorporate the oxophilic metal Ru into ultrathin PtNi nanowires, aiming to enhance the intrinsic activity of platinum while leveraging the long-term durability and high utilization efficiency provided by the bimetallic synergistic effect. The PtNiRu NWs significantly enhance both mass activity and specific activity for ORR, performing about 6.9 times and 3.9 times better than commercial Pt/C, respectively. After a rigorous durability test of 10,000 cycles, the PtNiRu NWs only exhibited a 25.2 % loss in mass activity. Additionally, for MOR, the MA and SA of PtNiRu NWs exceed that of Pt/C catalyst by 4.30 and 2.72 times, respectively, and exhibit exceptional resistance to CO poisoning. Theoretical insights from density functional theory calculations suggest that the introduction of Ru modulates the d-band center of the surface Pt atoms, which contributes to decreased binding strength of oxygenated species and an elevated dissolution potential, substantiating the enhanced performance metrics, and the durability enhancement stems from the stronger PtM bonds than those in PtNiRu NWs resulted from PtRu covalent interactions. These findings not only provide a new perspective on platinum-based nanocatalysts but also significantly advance the quest for more efficient and durable electrocatalysts for DMFCs, representing a substantial stride in fuel cell technology.

RESUMEN

Colonoscopies are widely available, but there are cases where insertion can be difficult, even for experienced endoscopists. EC-760XP/L, a new ultrasmall-diameter long scope, may be useful in such cases. This single-center retrospective study included 39 cases where colonoscope insertion was difficult even when previously conducted by an experienced endoscopist. The primary outcome was the cecal intubation time using EC-760XP/L compared to the time used in a previous examination with a standard scope. The secondary outcomes were the cecum intubation rate, intestinal cleanliness level, adenoma detection rate, polyp detection rate, sedative use rate, occurrence of adverse events, and pain experience. A comparison of cecal intubation times between EC-760XP/L and the standard scope showed that insertion times were significantly lower with EC-760XP/L (9.5 min) compared to the standard scope (19 min) (p < 0.01). The standard scope achieved cecal intubation in 30 cases (76.9%), whereas EC-760XP/L reached the cecum in all cases (p < 0.01). Pain was observed in 3 cases (8.3%) with the EC-760XP/L, which was significantly lower than the 22 cases (56.4%) with the standard scope (p < 0.01). In conclusion, EC-760XP/L proved to be useful in cases where colonoscope insertion was difficult.

Asunto(s)

RESUMEN

BACKGROUND: A 3.0-mm ultrathin bronchoscope (UTB) with a 1.7-mm working channel provides better accessibility to peripheral bronchi. A 4.0-mm thin bronchoscope with a larger 2.0-mm working channel facilitates the use of a guide sheath (GS), ensuring repeated sampling from the same location. The 1.1-mm ultrathin cryoprobe has a smaller diameter, overcoming the limitation of the size of biopsy instruments used with UTB. In this study, we compared the endobronchial ultrasound localization rate and diagnostic yield of peripheral lung lesions by cryobiopsy using UTB and thin bronchoscopy combined with GS. METHODS: We retrospectively evaluated 133 patients with peripheral pulmonary lesions with a diameter less than 30 mm who underwent bronchoscopy with either thin bronchoscope or UTB from May 2019 to May 2023. A 3.0-mm UTB combined with rEBUS was used in the UTB group, whereas a 4.0-mm thin bronchoscope combined with rEBUS and GS was used for the thin bronchoscope group. A 1.1-mm ultrathin cryoprobe was used for cryobiopsy in the two groups. RESULTS: Among the 133 patients, peripheral pulmonary nodules in 85 subjects were visualized using r-EBUS. The ultrasound localization rate was significantly higher in the UTB group than in the thin bronchoscope group (96.0% vs. 44.6%, respectively; P < 0.001). The diagnostic yield of cryobiopsy specimens from the UTB group was significantly higher compared to the thin bronchoscope group (54.0% vs. 30.1%, respectively; p = 0.006). Univariate analysis demonstrated that the cryobiopsy diagnostic yields of the UTB group were significantly higher for lesions ≤ 20 mm, benign lesions, upper lobe lesions, lesions located lateral one-third from the hilum, and lesions without bronchus sign. CONCLUSIONS: Ultrathin bronchoscopy combined with cryobiopsy has a superior ultrasound localization rate and diagnostic yield compared to a combination of cryobiopsy and thin bronchoscopy.

Asunto(s)

RESUMEN

Aqueous battery with nonflammable and instinctive safe properties has received great attention. However, issues related to Zn anode such as side reactions and rampant dendrite growth hinder the long-term circulation of AZMBs. Herein, an ultrathin(35 nm) MoO3 coating is deposited on the Zn anode by means of vacuum vapor deposition for the first time. Due to the peculiar layer structure of MoO3, insertion of Zn2+ in ZnxMoO3 acts as Zn2+ ion conductor, which regulates Zn2+ deposition in an ordered manner. Additionally, the MoO3 coating can also inhibit the hydrogen evolution and corrosion reactions at the interface. Therefore, both Zn//MoO3@Cu asymmetric battery and Zn symmetric battery cells manage to deliver satisfactory electrochemical performances. The symmetric cell assembled with MoO3@Zn shows a significant long cycle life of more than 1600 h at a current density of 2 mA cm-2. Meanwhile, the MoO3@Zn//Cu asymmetric cell exhibits an ultrahigh Zn deposition/stripping efficiency of 99.82% after a stable cycling of 650 h at 2 mA cm-2. This study proposes a concept of "zincophile Zn2+ conductor regulation" to dictate Zn electrodeposition and broadens novel design of vacuum evaporation for nano MoO3 modified Zn anodes.

RESUMEN

Ferroelectricity has recently been demonstrated in germanium-based halide perovskites. We use first-principles-based simulations to study 4-18 nm CsGeBr3 films and develop a theory for ferroelectric ultrathin films. The theory introduces (i) a local order parameter, which identifies phase transitions into both monodomain and polydomain phases, and (ii) a dipole pattern classifier, which allows efficient and reliable identification of dipole patterns. Application of the theory to both halides CsGeBr3 and CsGeI3 and oxide BiFeO3 ultrathin ferroelectrics reveals two distinct scenarios. First, the films transition into a monodomain phase below the critical value of the residual depolarizing field. Above this critical value, the second scenario occurs, and the film undergoes a transition into a nanodomain phase. The two scenarios exhibit opposite responses of Curie temperature to thickness reduction. Application of a dipole pattern classifier reveals rich nanodomain phases in halide films: nanostripes, labyrinths, zig-zags, pillars, and lego domains.

RESUMEN

Highly-efficient and cost-effective electrocatalysts toward the oxygen evolution reaction (OER) are crucial for advancing sustainable energy technologies. Herein, a novel approach leveraging corrosion engineering is presented to facilitate the in situ growth of amorphous cobalt-iron hydroxides on nickel-iron foam (CoFe(OH)x-m/NFF) within a NaCl-CoCl2 aqueous solution. By adjusting the concentration of the solution, the compositions can tailored and morphologies of these hydroxides to optimize the OER electrocatalytic performance. Specifically, the CoFe(OH)x-500/NFF electrode manifests as distinctive 3D flower-like clusters composed of remarkably thin nanosheets, measuring a mere 1 nm in thickness. By virtue of the amorphous and ultrathin nanosheet structure, the CoFe(OH)x-500/NFF electrode exhibits superior OER activity, characterized by notably low overpotentials (η100, 274 mV) and an exceptionally small Tafel slope of 40.54 mV dec-1. Moreover, the electrode's performance remains robust, maintaining low overpotentials for 168 h at 100 mA cm-2. In situ Raman spectroscopy indicates that the hydroxides experience surface structural reconstruction and transform into high-valent CoFeO2 with active Co(IV)-O sites during the OER. Theoretical calculations underscore the critical role of the NiFe substrate in enhancing the electrode's OER activity by improving electrical conductivity and modifying the adsorption energy of reaction intermediates, thereby reducing the energy barrier for the reaction.

RESUMEN

The observation of superconductivity in MnSe at 12 GPa motivated us to investigate whether superconductivity could be induced in MnSe at ambient conditions. A strain-induced structural change in the ultrathin film could be one route to the emergence of superconductivity. In this report, we present the physical property of MnSe ultrathin films, which become tetragonal (stretched ab-plane and shortened c-axis) on a (001) SrTiO3 (STO) substrate, prepared by the pulsed laser deposition (PLD) method. The physical properties of the tetragonal MnSe ultrathin films exhibit very different characteristics from those of the thick films and polycrystalline samples. The tetragonal MnSe films show substantial conductivity enhancement, which could be associated with the presence of superparamagnetism. The optical absorption data indicate that the electron transition through the indirect bandgap to the conduction band is significantly enhanced in tetragonal MnSe. Furthermore, the X-ray Mn L-edge absorption results also reveal an increase in unoccupied state valance bands. This theoretical study suggests that charge transfer from the substrate plays an important role in conductivity enhancement and the emergence of a ferromagnetic order that leads to superparamagnetism.

RESUMEN

The authors aim to provide a comprehensive overview of the advancements in head and neck reconstructive surgery using thinned perforator flaps. The article categorizes these flaps based on thickness and discusses the importance of standardized terminology. Critical aspects like flap vascularity, pre-operative planning, and imaging technologies for perforator mapping are examined with practical considerations. The article then delves into various thinning techniques and their applications in head and neck reconstructions, highlighting challenges and concerns. In conclusion, significant progress in reconstructive surgery using thinned perforator flaps has brought advancements in improving surgical precision and patient outcomes in head and neck reconstructions.

RESUMEN

Nanoparticle surfactants assembled at water-oil interfaces can significantly lower the interfacial tension and can be used to stabilize liquids. Understanding and actively tuning the mechanical properties of the generated membranes, which comprise the nanoparticle surfactants, are of significant fundamental interest for the interfacial behavior of nanoparticles and of interest for water purification, drug encapsulation, enhanced oil recovery, and innovative energy transduction applications. Here, we present electrostatic interaction-driven fabrication of freestanding and close-packed SiO2 surfactant membranes with diameters up to 0.10 mm. The membranes of 20-30 nm in thickness were spanned over holes with a diameter of 2 µm, exhibiting a Young's modulus ranging from 1.5 to 5.9 GPa. The controllable elastic properties of the fabricated nanoparticle surfactant membranes are found to be dictated by the strength of interactions between nanoparticles and ligands, between ligands and ligands, and between the nanoparticle surfactants. The results present an efficient approach for fabricating and developing nanoparticle surfactant-based large-area, freestanding, and ultrathin membranes with finely tunable mechanical properties on a large scale.

RESUMEN

The rational design and synthesis of novel semiconductor nano-/quantum materials have been ambitiously pursued in the field of photocatalysis as the technology is promising and critical for attaining future energy and environmental sustainability. Herein, the integrity of aromatic carbon into graphitic carbon nitride (CN) at the same molecular plane with a few 2D layers is achieved by using modulated precursors of CN, forming carbon regulated ultrathin CN (CUCN) with improved charge transfer kinetics and photocatalytic hydrogen production. The grafted graphite rings adjacent to carbon nitride frameworks induce a significant rearrangement and relocalization of the overall framework, and form conjugated sp2 hybridized interfaces and internal electric fields that drive the separation and directional transfer of photogenerated electrons from CN sheets towards intralayer graphite regions, where the photocatalytic hydrogen evolution reaction occurs extensively, yielding largely increased HER rate of 2231.8 µmol g-1 h-1 by 8.2 times relative to CN, as well as a remarkable apparent quantum yield of 2.93% under monochromatic light at 420 nm. The high physicochemical stability and low synthesis cost of CUCN make it a potential benchmark photocatalyst that can be readily modified via element doping, heterojunction introduction, defect engineering, and so on, to further enhance its HER performance.

RESUMEN

Ultrathin organic nanofibers (UTONFs) represent an emerging class of nanomaterials as they carry a set of favorable attributes, including ultrahigh specific surface area, lightweight, and mechanical flexibility, over inorganic counterparts, for use in biomedicine and nanotechnology. However, precise synthesis of uniform UTONFs (diameter ≤ 2 nm) with tailored functionalities remained challenging. Herein, we report robust multifunctional UTONFs using hydrophobic interaction-driven self-assembly of amphiphilic alternating peptoids containing hydrophobic photoresponsive azobenzene and hydrophilic hydroxyl moieties periodically arranged along the peptoid backbone. Notably, the as-crafted UTONFs are approximately 2 nm in diameter and tens of micrometers in length (an aspect ratio, AR, of ∼10000), exemplifying the UTONFs with the smallest diameter yielded via self-assembly. Intriguingly, UTONFs were disassembled into short-segmented nanofibers and controllably reassembled into UTONFs, resembling "step-growth polymerization". Photoisomerization of azobenzene moieties leads to reversible transformation between UTONFs and spherical micelles. Such meticulously engineered UTONFs demonstrate potential for catalysis, bioimaging, and antibacterial therapeutics. Our study highlights the significance of the rational design of amphiphiles containing alternating hydrophobic and hydrophilic moieties in constructing otherwise unattainable extremely thin UTONFs with ultrahigh AR and stimuli-responsive functionalities for energy and bionanotechnology.

RESUMEN

The construction of ultrathin porous membranes with stable structures is critical for achieving efficient gas separation. Inspired by the binary-cooperative structural features of bones and teeth-composed of rigid hydroxyapatite and flexible collagen, which confer excellent mechanical strength-a binary-cooperative porous membrane constructed with gel-state zeolitic imidazolate frameworks (g-ZIFs), synthesized using a metal-gel-induced strategy, is proposed. The enlarged cavity size and flexible frameworks of the g-ZIF nanoparticles significantly improve gas adsorption and diffusion, respectively. After thermal treatment, the coordination structures forming rigid segments in the g-ZIF membranes appear at the stacked g-ZIF boundaries, exhibiting a higher Young's modulus than the g-ZIF nanoparticles, denoted as the flexible segments. The g-ZIF membranes demonstrate excellent tensile and compression resistances, attributed to the effective translation of binary-cooperative effects of rigidity and flexibility into the membranes. The resulting dual-aperture structure, composed of g-ZIF nanoparticles surrounded by nanoscale apertures at the boundaries, yields a membrane with a stable CO2 permeance of 4834 GPU and CO2/CH4 selectivity of 90 within 3.0 MPa.

RESUMEN

Lithium-sulfur (Li-S) batteries present significant potential for next-generation high-energy-density devices. Nevertheless, obstacles such as the polysulfide shuttle and Li-dendrite growth severely impede their commercial production. It is still hard to eliminate gaps between individual particles on separators that serve as potential conduits for polysulfide shuttling. Herein, the synthesis of a nanoscale thickness and defect-free cross-linked polyamide (PA) layer on a polypropylene (PP) separator is presented through in situ polymerization. The PA modification layer can effectively impede the diffusion of polysulfides with a thickness of only 1.5 nm, as evidenced by the results of cyclic voltammetry (CV) and time-of-flight (TOF) testing. Therefore, the Li/Li symmetric battery assembled with the functional separator exhibits an overpotential of merely 12 mV after 1000 h of cycling under test conditions of 1 mA cm-2-1 mAh cm-2. Furthermore, the capacity degradation rate of the Li-S battery is only 0.06% per cycle over 450 cycles at 1 C, while the Li-S pouch cell retains 87.63% of its capacity after 50 cycles. This work will significantly advance the preparation and application of molecules in Li-S batteries, and it will also stimulate further research on defect-free modification of separators.

RESUMEN

Epitaxial strain plays an important role in the stabilization of ferroelectricity in doped hafnia thin films, which are emerging candidates for Si-compatible nanoscale devices. Here, we report on epitaxial ferroelectric thin films of doped HfO2 deposited on La0.7Sr0.3MnO3-buffered SrTiO3 substrates, La0.7Sr0.3MnO3 SrTiO3-buffered Si (100) wafers, and trigonal Al2O3 substrates. The investigated films appear to consist of four domains in a rhombohedral phase for films deposited on La0.7Sr0.3MnO3-buffered SrTiO3 substrates and two domains for those deposited on sapphire. These findings are supported by extensive transmission electron microscopy characterization of the investigated films. The doped hafnia films show ferroelectric behavior with a remanent polarization up to 25 µC/cm2 and they do not require wake-up cycling to reach the polarization, unlike the reported polycrystalline orthorhombic ferroelectric hafnia films.

RESUMEN

Electronic tattoo, capable of imperceivably acquiring bio-electrical signals from the body, is broadly applied in healthcare and human-machine interface. Tattoo substrate, the foundation of electronic tattoo, is expected to be mechanically mimetic to skin, adhesive, and breathable, and yet remains highly challenging to achieve. Herein, the study mimics human skin and design a breathable, adhesive, and mechanically skin-like super tattoo substrate based on an ultra-thin film (≈2 µm). Similar to skin, super tattoo demonstrates strain-adaptive stiffening properties with high tear energy (5.4 kJ·m-2) and toughness (1.3 MJ·m-3). Superior to skin, it exhibits high adhesion, ionic conductivity, and permeability. A variety of conductive electrodes can be processed on it, showing the universality toward an ideal platform for electronic tattoo with stable and low contact impedance. Super tattoo-based electrodes can imperceivably and accurately monitor weak electromyography (EMG) of swallowing on the junction, providing effective guidance for rehabilitation training of dysphagia.

RESUMEN

Solid polymer electrolytes (SPEs) are promising for high-energy-density solid-state Li metal batteries due to their decent flexibility, safety, and interfacial stability. However, their development was seriously hindered by the interfacial instability and limited conductivity, leading to inferior electrochemical performance.  Herein, we proposed to design ultra-thin solid-state electrolyte with long-range cooperative ion transport pathway to effectively increase the ionic conductivity and stability. The impregnation of PVDF-HFP inside pores of  fluorinated covalent organic framework (CF3-COF) can disrupt its symmetry, rendering rapid ion transportation and inhibited anion imigration. The functional groups of CF3-COF can interact with PVDF-HFP to form fast Li+ transport channels, which enables the uniform and confined Li+ conduction within the electrolyte. The introduction of CF3-COF also enhances the mechanical strength and flexibility of SPEs, as well as ensures homogeneous Li deposition and inhibited dendrite growth.  Hence, a remarkably high conductivity of 1.21×10-3 S cm-1 can be achieved. Finally, the ultra-thin SPEs with an extremely long cycle life exceed 9000 h can be obtained (the longest cycle life reported until now) while the NCM523/Li pouch cell demonstrates a high capacity of 760 mAh and 96% capacity retention after cycling, holding great promises to be utilized for practical solid-state Li metal batteries.

RESUMEN

The mass transport and ion conductivity in the catalyst layer are important for fuel cell performances. Here, we report an in situ-grown ultrathin catalyst layer (UTCL) to reduce the oxygen mass transport and a surface ionomer-coated gas diffusion layer method to reduce the ion conducting resistance. A significantly reduced catalyst layer thickness (ca. 1 µm) is achieved, and coupled with the ionomer introduction method, the ultrathin catalyst layer is in good contact with the membrane, resulting in high ion conductivity and high Pt utilization. This ultrathin catalyst layer is suitable for both proton exchange membrane fuel cells and anion exchange membrane fuel cells, giving peak power densities of 2.24 and 1.11 W cm-2, respectively, which represent an increase of more than 30% compared with the membrane electrode assembly (MEA) fabricated by using traditional Pt/C power catalysts. Electrochemical impedance spectra and limiting current tests demonstrate the reduced charge transfer, mass transfer, and ohmic resistances in the ultrathin catalyst layer membrane electrode assembly, resulting in the promoted fuel cell performances.